How We Made This '85 Run "Uncommonly Good"

Step By Step

We originally ordered the 300hp engine, but GM built a limited number of them, so they substituted the 330hp engine in its place. The only difference between the two engines is that the 330hp engine uses the Vortec cylinder heads, from which sprung the first gremlin. (See sidebar Head Games.)

Chris uses a different pan (PN 10055765) to ensure proper ground clearance in a Corvette. He says the crate engines original one- piece rear seal pan will work, but the pan is lower than the front crossmember and could bottom out.

Youll need to get an externally balanced flywheel to use on the new engine and order new flywheel bolts (PN 14088764). Be sure to torque the flywheel bolts to 65 lb-ft. Excessive torque on the bolts will result in oil leaks.

Youll have to find an ECM (PN 1227165) and wiring harness from an 89 Corvette. The wiring harness will need some modifications. Youll also need a service manual from an 85 and an 89 so you can compare the differences between the two systems.

He also uses relay (PN 14089936) to operate the MAF power, MAF burn-off signal, and the fuel pump. The poor condition of the wires is due to GMs use of a corrosion inhibitor. While it slowed corrosion of the connection, it reacted with the insulation of the wires. This is not uncommon, and should be repaired while doing the install.

After we got the heads and intake to mate together, we were ready to install the engine. Or so we thought. We noticed a little drip by the drain hole in the oil pan. We wiped it off and tightened up the oil plug, figuring that would do the trick.

Chris likes to install all of the engine components in what he calls layers. The wiring harness was installed next because some of the wires will have to be positioned before the rest of the parts are installed. Take your time in positioning the wires and make sure that they wont be affected by heat or rub against other components, which can greatly shorten their life.

After the wiring was situated, Chris started installing the parts that would reside under the plenum. Because of the placement and condition of the injectors, Chris replaced them with new injectors to ensure trouble-free operation. This operation is much easier to do now instead of having to remove everything later.

The next items to be installed are the components on the front of the engine. Youll notice that Chris has retained the air pump. Every engine he installs uses the emissions equipment that pertains to the year of vehicle for which it is installed. He believes its important to use todays technology to keep emissions low, without hurting fuel economy or performance.

Chris decided to go with a 52mm throttle body supplied by Edelbrock. He suggests going no larger than 52mm unless there is sufficient increase in the cubic inches of the engine, because the velocity of airflow will drop and the bottom-end throttle response will suffer.

As Chris installs components on the engine, he likes to run the wiring so that the wires can be neatly run over or around the engine and make sure to keep all wires away from situations where they can rub or burn through. Here hes deciding how the ignition wires are going to be run.

Notice that not all of the ends of the wires are the same. The straight end is for the No. 6 spark plug. Chris also primes each engine by using an old distributor shaft machined to fit into a 3/8-inch drill bit to turn the oil pump and supply oil to all of the moving parts before firing the engine.

With the wiring and the distributor installed, Chris begins working on the air-cleaner ductwork. Another gremlin rears its ugly head during this step. The bolts that hold the air-filter-duct housing to the radiator support would spin hopelessly in the radiator support, so they had to be repaired.

Chris moves the AIT (air intake temp) sensor from the plenum to the air-cleaner-housing assembly. This gives a more accurate air temp reading because the sensor is not preheated by the heat of the plenum. He drills a 5/8-inch hole in the air-cleaner assembly and then trims the hole to fit.

With the wires, hoses, belts, and intake housing installed, Chris lifts the car up on the hoist and begins to finish the exhaust system. He cut the original pipes, and welds flanges on them to mate to the Hooker headers. He slips the collector flanges over the outside of the pipes and welds them inside and out to ensure a good seal.

Because the exhaust system is a double-walled design, welding inside reduces soot buildup between the two walls of the pipe. He tack-welds the new pipes while bolted to the headers and then unbolts the collectors to finish the welds.

Once everything is installed, Chris fills the oil, coolant, and transmission fluids. Another important step is to ensure that the linkages are working properly, and that nothing will cause them to stick. Chris also adjusts the TV cable that is supplied with the transmission. Adjusting the cable is done by pushing in on the retainer with a screwdriver while pushing in on the cable. Then, with the engine turned off, push the gas pedal to the floor to set the cable. This is important for longevity of the transmission because the transmissions valve body needs to be in adjustment with the throttle opening.

Kevin Schylaske drives a Keebler Cookies truck to make a living, but when he wants to live life to the fullest, he drives his '85 Corvette. He enjoyed his Corvette until the engine overheated and distorted the machined surfaces like a funhouse mirror. Understanding that it would take more than just a little "Elfin Magic"(R) to make his Corvette run again, he took it to Chris Petris at the Corvette Clinic in Sanford, Florida.

Chris suggested that he step up to a GM Performance Parts crate engine, and upgrade the ECM and wiring to '89 standards. Benefits of this swap include more horsepower and better engine controls. With the '89 MAF system, the processor is more tunable than the '85 (due to more versatile chips), and the '89 has a faster processor that reacts faster to changes while the engine is operating. Chris also eliminates the ECM's need for information from the VATS system by reprogramming the chip. The overall package comes together to provide a reliable system that will push out plenty of "elf-power."

This engine swap provided some interesting gremlins for Chris and his team, but clear thinking, along with help from friends like Edelbrock and Fourth Gear, made this engine swap more than just a "cookie cutter" installation.

The completed engine looks as good as it runs. There were some trials along the way, but the look on Kevins face when he hits the go-pedal will make it all worthwhile. The engine began as a 330hp engine and Chris says that, with the increase in airflow from the large-tube runners, Edelbrock heads, and throttle body, 350 hp is not out of the question. The TPI will also increase driveability and efficiency while providing for smog-free operation. With all that horsepower and fun on tap, Kevin is sure to be taking all of his Keebler friends for a ride.

Sources

Note: Uncommonly Good and Elfin Magic are registered trademarks and are used with the permission of Keebler Company.

We originally ordered the 300hp engine, but GM built a limited number of them, so they substituted the 330hp engine in its place. The only difference between the two engines is that the 330hp engine uses the Vortec cylinder heads, from which sprung the first gremlin. (See sidebar Head Games.)

Chris uses a different pan (PN 10055765) to ensure proper ground clearance in a Corvette. He says the crate engines original one- piece rear seal pan will work, but the pan is lower than the front crossmember and could bottom out.

Changing the pan will require changing the oil pickup tube and screen with PN 12550106.

Youll need to get an externally balanced flywheel to use on the new engine and order new flywheel bolts (PN 14088764). Be sure to torque the flywheel bolts to 65 lb-ft. Excessive torque on the bolts will result in oil leaks.

Chris uses the engine-cooling package that was included within option VO8, which includes a pusher fan and an oil cooling system. The oil cooler can keep oil temperature about 20 degrees cooler.

Youll have to find an ECM (PN 1227165) and wiring harness from an 89 Corvette. The wiring harness will need some modifications. Youll also need a service manual from an 85 and an 89 so you can compare the differences between the two systems.

He also uses relay (PN 14089936) to operate the MAF power, MAF burn-off signal, and the fuel pump. The poor condition of the wires is due to GMs use of a corrosion inhibitor. While it slowed corrosion of the connection, it reacted with the insulation of the wires. This is not uncommon, and should be repaired while doing the install.

The modified wiring harness.

Here we put the finishing touches on the transmission supplied by Fourth Gear. They offer 700-R4 transmissions to suit their customers needs.

The ceramic-coated headers were supplied by Hooker Headers (HO 2149) and are equipped with air tubes for emissions compliance.

Chris prefers the starters that were used on LT1 and LT4 engines because of the geardrive reduction, their size, and reliability.

After we got the heads and intake to mate together, we were ready to install the engine. Or so we thought. We noticed a little drip by the drain hole in the oil pan. We wiped it off and tightened up the oil plug, figuring that would do the trick.

An hour later another drip had formed! A close inspection revealed that the new oil pan had a crack in it. A new one would have to be ordered to finish the job right. Another gremlin.

After we replaced the faulty pan, we continued to install the engine and 700-R4 transmission. When everything was tight underneath, we lowered the car and began working on the topside of the engine.

Chris likes to install all of the engine components in what he calls layers. The wiring harness was installed next because some of the wires will have to be positioned before the rest of the parts are installed. Take your time in positioning the wires and make sure that they wont be affected by heat or rub against other components, which can greatly shorten their life.

After the wiring was situated, Chris started installing the parts that would reside under the plenum. Because of the placement and condition of the injectors, Chris replaced them with new injectors to ensure trouble-free operation. This operation is much easier to do now instead of having to remove everything later.

The next items to be installed are the components on the front of the engine. Youll notice that Chris has retained the air pump. Every engine he installs uses the emissions equipment that pertains to the year of vehicle for which it is installed. He believes its important to use todays technology to keep emissions low, without hurting fuel economy or performance.

Chris opted for a set of large-tube runners and modified plenum that he had in his shop to increase the operating rpm and horsepower potential of the engine.

Chris decided to go with a 52mm throttle body supplied by Edelbrock. He suggests going no larger than 52mm unless there is sufficient increase in the cubic inches of the engine, because the velocity of airflow will drop and the bottom-end throttle response will suffer.

As Chris installs components on the engine, he likes to run the wiring so that the wires can be neatly run over or around the engine and make sure to keep all wires away from situations where they can rub or burn through. Here hes deciding how the ignition wires are going to be run.

In preparation to install the distributor, each wire is numbered according to the cylinder it represents. This makes setting the firing order much easier and quicker.

Notice that not all of the ends of the wires are the same. The straight end is for the No. 6 spark plug. Chris also primes each engine by using an old distributor shaft machined to fit into a 3/8-inch drill bit to turn the oil pump and supply oil to all of the moving parts before firing the engine.

With the wiring and the distributor installed, Chris begins working on the air-cleaner ductwork. Another gremlin rears its ugly head during this step. The bolts that hold the air-filter-duct housing to the radiator support would spin hopelessly in the radiator support, so they had to be repaired.

Chris reports that this is a typical problem with these bolts, and simply drills the clips that hold the bolt and puts a pop rivet through the clip and the radiator support.

Chris moves the AIT (air intake temp) sensor from the plenum to the air-cleaner-housing assembly. This gives a more accurate air temp reading because the sensor is not preheated by the heat of the plenum. He drills a 5/8-inch hole in the air-cleaner assembly and then trims the hole to fit.

Chris inserts the sensor through the hole.

Due to the air-cleaner assemblys plastic construction, well get a more accurate reading of the air temperature. This will result in better control of the air/fuel mixture.

With the wires, hoses, belts, and intake housing installed, Chris lifts the car up on the hoist and begins to finish the exhaust system. He cut the original pipes, and welds flanges on them to mate to the Hooker headers. He slips the collector flanges over the outside of the pipes and welds them inside and out to ensure a good seal.

Because the exhaust system is a double-walled design, welding inside reduces soot buildup between the two walls of the pipe. He tack-welds the new pipes while bolted to the headers and then unbolts the collectors to finish the welds.

Once everything is installed, Chris fills the oil, coolant, and transmission fluids. Another important step is to ensure that the linkages are working properly, and that nothing will cause them to stick. Chris also adjusts the TV cable that is supplied with the transmission. Adjusting the cable is done by pushing in on the retainer with a screwdriver while pushing in on the cable. Then, with the engine turned off, push the gas pedal to the floor to set the cable. This is important for longevity of the transmission because the transmissions valve body needs to be in adjustment with the throttle opening.